Study: Like Humans, Pigs Can be Optimists or Pessimists

A new study published in the journal The Royal Society has found that pigs have unique personality traits that allow them to be optimists or pessimists. These results suggest that “judgement in non-human animals is similar to humans, incorporating aspects of stable personality traits and more transient mood states.”

In humans, “mood and personality interact to determine cognitive bias, but to date, this has not been investigated in non-human animals”, states the study’s abstract. “Here, we demonstrate for the first time, to the best of our knowledge, in a non-human animal, the domestic pig (Sus scrofa domesticus), that mood and personality interact, impacting on judgement.”

The study found that “Pigs with a more proactive personality were more likely to respond optimistically to unrewarded ambiguous probes (spatially positioned between locations that were previously rewarded and unrewarded) independent of their housing (or enrichment) conditions. However, optimism/pessimism of reactive pigs in this task was affected by their housing conditions, which are likely to have influenced their mood state.”

It continues; “Reactive pigs in the less enriched environment were more pessimistic and those in the more enriched environment, more optimistic.”

According to researchers, these results “suggest that judgement in non-human animals is similar to humans, incorporating aspects of stable personality traits and more transient mood states.”

The study, published earlier this month, can be found by clicking here.